Neurocognition and social cognition in youth and young adults at ultra-high-risk for psychosis and bipolar disorder

BACKGROUND

Schizophrenia and bipolar disorder are associated with significant deficits in neurocognition and social cognition. Unlike the studies in chronic stages of these disorders, very limited information is available regarding neurocognitive and social-cognitive impairment before the onset of bipolar disorder. Our main aim was to investigate the differences in neurocognition and social cognition between individuals at ultra-high risk for psychosis (UHR-P) and bipolar disorder (UHR-BD).

METHODS

This study included 152 help-seeking individuals identified as UHR-P (n = 78) and UHR-BD (n = 74), who were compared with a healthy control group (n = 43). A comprehensive neuropsychological battery was administered to all participants.

RESULTS

UHR-P was associated with widespread deficits in all neurocognitive and social-cognitive domains. Effect sizes (Cohen's d) of these deficits ranged from -0.57 to -1.34. UHR-BD was associated with significant deficits in processing speed, executive functions, sustained attention and social cognition (d = -0.48 to-0.70, p < 0.05). UHR-P performed significantly worse than UHR-BD in social cognition, processing speed, verbal memory and executive function domains (d = -0.39 to-0.64, p < 0.05). Negative symptoms were associated with impaired social cognition in the UHR-P group and verbal memory deficits in the UHR-BD group. Cognitive impairment was associated with functional impairment in both groups.

CONCLUSIONS

While UHR-P is associated with more widespread cognitive impairment, deficits in processing speed, executive functions, sustained attention and social cognition might be common features of both UHR groups. In early intervention services, cognition should be considered as a target for assessment and intervention not only for individuals at high risk for psychosis but also for bipolar disorder.

Are Communication Skills, Emotion Regulation and Theory of Mind Skills Impaired in Adolescents with Developmental Dyslexia?

This study investigates pragmatic language impairment, Theory of Mind (ToM), and emotion regulation in adolescents with Developmental Dyslexia(DD). The Social Responsiveness Scale-2(SRS) and Children's Communication Checklist-2(CCC-2) scores were found to be statistically significantly higher in the DD group than in healthy controls. DD group had lower performance in ToM skills and they have more difficulties in emotion regulation. We also found that CCC-2 and ToM scores were significantly correlated in adolescents with DD. These results may be important in understanding the difficulties experienced in social functioning and interpersonal relationships in adolescents with DD.

Differential Effects of Disruptive Mood Dysregulation Disorder Comorbidity in Attention Deficit Hyperactivity Disorder on Social Cognition and Empathy

OBJECTIVE

This study aimed to investigate social cognition and empathy properties in children among Disruptive Mood Dysregulation Disorder (DMDD) + Attention and Hyperactivity Disorder(ADHD); ADHD and healthy controls from Türkiye.

METHODS

Twenty-two children with DMDD were compared to matched 30 children with ADHD and 60 healthy controls. We administered Affective Reactivity Index (ARI), KaSi Empathy Scale, Kiddie-SADS, and Reading Mind in the Eyes Test (RMET) to evaluate Theory of Mind skills to all study participants.

RESULTS

DMDD + ADHD group had lower performance in ToM skills and empathy than in two groups. The ARI scores were found to be statistically significantly higher in the DMDD group than in two groups. It was also found that ARI, empathy, and ToM scores were significantly related in children with DMDD + ADHD.

CONCLUSION

These results might be important to understand the difficulties in social functioning and interpersonal relationship in children with DMDD and ADHD. Children with DMDD may attend specific therapeutic programs which include specific techniques in social cognition, emotion regulation, and irritability.

Risk factors for brachial plexus injury and permanent sequelae due to shoulder dystocia

AIM

The primary aim of this study was to determine the risk factors for the occurrence of brachial plexus injury in cases of shoulder dystocia. Secondly, it was aimed to determine the factors affecting the occurrence of permanent sequelae in cases with brachial plexus injury.

SUBJECTS AND METHODS

ICD-10 codes were scanned from the records of patients who gave birth between 2012 and 2018, and the records of patients with brachial plexus injury and shoulder dystocia were reached. Shoulder dystocia cases with brachial plexus damage were accepted as the study group, and shoulder dystocia cases without brachial plexus damage were considered the control group. Shoulder dystocia patients with brachial plexus injury and without injury were compared for 2-year orthopedics clinic follow-up reports, surgical intervention, permanent sequelae status as well as birth data, maternal characteristics, and maneuvers applied to the management of shoulder dystocia.

RESULTS

Five hundred sixty births with shoulder dystocia were detected. Brachial plexus injury was observed in 88 of them, and permanent sequelae were detected in 12 of these patients. Maneuvers other than McRobert's (advanced maneuvers) were used more and clavicle fracture was seen more in the group with plexus injury (P < 0.05, P < 0.05, respectively). Logistic regression analysis was performed to determine the risk factors of brachial plexus injury. Brachial plexus injury was observed 4.746 times more in infants who were delivered with advanced maneuvers and 3.58 times more in infants with clavicle fractures at birth.

CONCLUSION

In patients with shoulder dystocia, the risk of brachial plexus injury increased in deliveries in which advanced maneuvers were used and clavicle fracture occurred.

The association between pragmatic language impairment, social cognition and emotion regulation skills in adolescents with ADHD

OBJECTIVE

Attention Deficit and Hyperactivity Disorder (ADHD) is associated with significant pragmatic language impairment and theory of mind deficits, but there are only a handful of studies have investigated the relationship between them in these conditions. This study aimed that investigate two different aspects of Theory of Mind (ToM) (ToM decoding and reasoning), pragmatic language impairment, and emotion regulation in patients with ADHD.

METHOD

Seventy adolescents with ADHD were compared to matched 64 healthy controls. We administered Social Responsiveness Scale-2 (SRS-2), Difficulties in Emotion Regulation Scale (DERS), Kiddie-SADS, Conners Parent Rating Scale, Children's Communication Checklist-2 (CCC-2), Faux Pas, Comprehension Test, and Reading Mind in the Eyes Test (RMET) to all study participants.

RESULTS

The CCC-2 scores were found to be statistically significantly higher in the ADHD group than in healthy controls. ADHD group had lower performance in the Faces Test and RMET compared to healthy controls, which did not survive from false discovery rate correction. We also found that CCC-2 performance and Conners scores were significant predictors of social responsiveness.

CONCLUSION

Our results point to widespread impairment in pragmatic language use and communication from many perspectives. These results might be important to understand the difficulties in social functioning and interpersonal relationship in adolescents with ADHD.Key pointsADHD is associated with significant impairment in pragmatic language use and social cognitive functions.ToM-Decoding (RMET) is impaired much more than ToM-Reasoning (Faux Pas) in ADHD.Pragmatic language skills and severity of ADHD may be significant predictors of social responsiveness.Emotion regulation problems may affect communication and pragmatic language use.

Family functioning and quality of life among children with anxiety disorder and healthy controls. A cross-sectional study

BACKGROUND

Studies have shown that children with anxiety disorders (ADs) present impaired family functioning and quality of life. We aimed to evaluate family functioning and quality of life among children with AD and healthy controls.

DESIGN AND SETTING

Cross-sectional study (survey) at two centers in Turkey.

METHODS

The study group comprised 42 children diagnosed with AD and 55 controls. The Screen for Child Anxiety-Related Emotional Disorders (SCARED) questionnaire was filled out by their parents to measure the severity of anxiety symptoms. Family functioning among the children was assessed using the Family Assessment Device (FAD) and Parental Attitude Research Instrument (PARI). The children's quality of life was assessed through the Pediatric Quality of Life Inventory (PedsQL).

RESULTS

The children's average age was 10.00 ± 0.21 years in the AD group and 9.98 ± 1.53 years among the controls. There were higher scores on all FAD subscales in the AD group (2.15 ± 0.52; 2.29 ± 0.44; 2.44 ± 0.55; 2.10 ± 0.61; 2.56 ± 0.40; 2.32 ± 0.33; and 2.29 ± 0.47). On PARI subscales, there were significant differences favoring the AD group (p < 0.05), except for democratic attitude. All PedsQL subscales differed significantly between the groups, favoring the AD group. A statistically significant relationship was found between all PedsQL subscales and SCARED scores in the AD group.

CONCLUSION

We found that both family functioning and quality of life among children with AD were negatively affected. However, further studies with larger sample sizes are required to reach stronger conclusions.

Evaluation of children's dental anxiety levels at a kindergarten and at a dental clinic

This study evaluated the dental anxiety levels of preschool children at a kindergarten and at a dental clinic. The anxiety levels of ninety 4-6-year-old (4.99 ± 0.81) preschool children were evaluated according to pulse rates, the facial image scale (FIS), the Venham picture test (VPT), and the Frankl behavior rating scale. The children's mothers were asked to complete the state-trait anxiety inventory (STAI) forms 1 and 2 (STAI 2 and STAI 2). The sample t-test, Mann-Whitney U test, and Pearson's correlation test were used. A statistically significant difference was observed between the children's pulse rates when measured at the dental clinic and those when measured at the kindergarten (p < 0.001). Although the results were not statistically significant, more negative facial expressions were observed in the children at the dental clinic than in those at the kindergarten when assessed using FIS and VPT (p = 0.090 and p = 0.108, respectively). There was a statistically significant correlation between the transient anxiety levels (STAI 1) of mothers and the VPT scores of their children evaluated at the dental clinic (r = 0.506, p < 0.001). The continuous anxiety level of the mothers of males was found to be significantly higher (p = 0.033) than that of the mothers of females (STAI 2). Although the children had been informed about dentistry and were introduced to a dentist at the kindergarten, their anxiety levels seemingly increased as they arrived at the dental clinic. The significant increase observed in the children's pulse rates was a physical indicator that their anxiety levels had increased. It can be concluded that the children felt more anxious at the dental clinic that at the kindergarten.

Fluctuation-dissipation and energy properties of a finite bath

This paper expands a recent proposal by the authors to rederive the Langevin equation for a test particle in a finite-size thermal bath using a perturbation approach that yields a cascade of Langevin-type equations. Such an approach produces a different viewpoint for the fluctuation-dissipation duality by expressing them on similar scales. General properties of energy sharing between the test particle and the bath are outlined, investigating the resonant and nonresonant conditions.

Decreased right hippocampal volumes and neuroprogression markers in adolescents with bipolar disorder

OBJECTIVES

The aim of the present study was to assess differences and correlations between the hippocampal volumes (HCVs), serum nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF) levels in adolescents with bipolar disorder (BP) compared to healthy controls.

METHODS

Using structural magnetic resonance imaging, we compared HCVs of 30 patients with euthymic BP who were already enrolled in a naturalistic clinical follow-up. For comparison, we enrolled 23 healthy controls between the ages of 13 and 19. The boundaries of the hippocampus were outlined manually. The BDNF and NGF serum levels were measured with the sandwich ELISA.

RESULTS

The groups did not differ in the right or left HCVs or in the NGF or BDNF serum levels. However, negative correlations were found between the right HCVs and the duration of the disorder and medication and positive correlations were found between the duration of the medications and the NGF and BDNF levels in the patient group. Additionally, positive correlations were found between the follow-up period and left normalized HCVs in both the BP and lithium-treated groups.

CONCLUSIONS

The right HCVs may vary with illness duration and the medication used to treat BP; NGF and BDNF levels may be affected by long-term usage. Further research is needed to determine whether these variables and their structural correlates are associated with clinical or functional differences between adolescents with BP and healthy controls.

Sleep Structure in Children With Attention-Deficit/Hyperactivity Disorder

The authors evaluated basic sleep architecture and non-rapid eye movement (NREM) sleep alterations in drug-naïve attention-deficit/hyperactivity disorder (ADHD) children without psychiatric or other comorbidities. This cross-sectional case-control study included 28 drug-naïve children with ADHD and 15 healthy controls. This subjective studies revealed that children with ADHD had a worse sleep quality and increased daytime sleepiness. Polysomnography data showed that the sleep macrostructure was not significantly different in children with ADHD. Sleep microstructure was altered in ADHD children by means of reduced total cyclic alternating pattern rate and duration of cyclic alternating pattern sequences. This reduction was associated with a selective decrease of A1 index during stage 2 NREM. SpO2 in total sleep was slightly decreased; however, the incidence of sleep disordered breathing showed no significant difference. The authors suggest that cyclic alternating pattern scoring would provide a further insight to obtain a better understanding of the sleep structure in children with ADHD.

Correlations between amygdala volumes and serum levels of BDNF and NGF as a neurobiological markerin adolescents with bipolar disorder

BACKGROUND

The amygdala is repeatedly implicated as a critical component of the neurocircuitry regulating emotional valence. Studies have frequently reported reduced amygdala volumes in children and adolescents with bipolar disorder (BD). Brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF) play critical roles in growth, differentiation, maintenance, and synaptic plasticity of neuronal systems in adolescent brain development. The aim of the present study was to assess amygdala volumesand its correlation with serum levels of NGF and BDNF in euthymic adolescents with BD and healthy controls.

METHODS

Using structural MRI, we compared the amygdala volumes of 30 euthymic subjects with BD with 23 healthy control subjects aged between 13 and 19 years during a naturalistic clinical follow-up. The boundaries of the amygdala were outlined manually. Serum BDNF and NGF levels were measured using sandwich-ELISA and compared between the study groups.

RESULTS

The right or left amygdala volume did not differ between the study groups.The right and left amygdala volumes were highly correlated with levels of BDNF in the combined BD group and the valproate-treated group.Both R and L amygdala volumes were correlated with BDNF levels in healthy controls. The left amygdala volumes were correlated with BDNF levels in the lithium-treated group.

LIMITATIONS

This cross-sectional study cannot inform longitudinal changes in brain structure. Further studies with larger sample sizes are needed to improve reliability.

CONCLUSIONS

The correlations between amygdala volumes and BDNF levels might be an early neuromarker for diagnosis and/or treatment response in adolescents with BD.

Assessment of neuropsychological late effects in survivors of childhood leukemia

The neurologic dysfunctions caused by treatment may affect health and quality of life in survivors of childhood leukemia. The objective of this study was to identify the neuropsychological late effects of leukemia treatment to provide an assessment about the degree and incidence of these late effects. Neurological and ophtalmological examination, cranial magnetic resonance imaging (MRI), auditory and neurocognitive tests, and questionnaires of quality of life were performed to 44 acute leukemia survivors at least 5 years after diagnosis. Median time since completion of chemotherapy was 7.5 years (2-18) and median age at the time of the study was 16.4 years (8-31). At least one or more late effects detected by physical examination (PE), neurological tests, or neurocognitive tests encountered in 80% of the patients, and 64% of the patients specified at least one complaint in the quality of life questionnaire. MRI revealed pathological findings in 18% and electroencephalogram (EEG) abnormalities were present in 9% of the patients. Evaluation of total intelligence scores revealed that 30% of patients' IQ scores were <80 and 70% of the patients' scores demonstrated neurocognitive dysfunctions. The patients >6 years at the time of diagnosis were found to have more psychological problems and higher rates of smoking and alcohol consumption. The most frequent complaint was headache and the most common problem in school was denoted as difficulty in concentration. Our study demonstrated that most of the survivors of childhood leukemia are at risk of developing neuropsycological late effects.

A novel data-mining platform leveraging social media to monitor outcomes of Januvia

A novel data-mining method was developed to gauge the experiences of the diabetes mellitus drug Januvia. Self-organizing maps were used to analyze forum posts numerically to infer user opinion of drug Januvia. Graph theory was used to discover influential users. The result is a word list compilation correlating positive and negative word cluster groups and a web of influential users on Januvia. The implications could open new research avenues into rapid data collection, feedback, and analysis that would enable improved solutions for public health.

A 12-month prospective, observational study of treatment regimen and quality of life associated with ADHD in central and eastern europe and eastern Asia

OBJECTIVES

This prospective, observational, non-randomized study aimed to describe the relationship between treatment regimen prescribed and the quality of life (QoL) of ADHD patients in countries of Central and Eastern Europe (CEE) and Eastern Asia over 12 months.

METHODS

977 Male and female patients aged 6-17 years seeking treatment for symptoms of ADHD were assessed using the Child and Adolescent Symptom Inventory-4 Parent Checklists, and the Clinical Global Impressions-ADHD-Severity scale. QoL was assessed using the Child Health and Illness Profile-Child Edition parent report form. Patients were grouped according to whether they were prescribed psycho- and/or pharmacotherapy (treatment) or not (no/'other' treatment).

RESULTS

No statistically significant differences were observed between cohorts (treatment vs. no/'other' treatment) in terms of change in QoL, although there was improvement over 12 months, with a greater improvement experienced by patients in the treatment cohort in both study regions (CEE and Eastern Asia). Psychoeducation/counselling and methylphenidate were the predominant ADHD treatments prescribed.

CONCLUSIONS

Although both treatment and no/'other' treatment cohorts showed improvements in mean QoL over 12 months, the difference was small and not statistically significant. A major limitation was the higher than anticipated number of patients switching treatments, predominantly from the no/'other' treatment cohort.

Dissipation in a finite-size bath

We investigate the interaction of a particle with a finite-size bath represented by a set of independent linear oscillators with frequencies that fall within a finite bandwidth. We discover that when the oscillators have particular frequency distributions, the finite-size bath behaves much as an infinite-size bath exhibiting dissipation properties and thus allowing irreversible energy absorption from a particle immersed in it. We also present a reinterpretation of the Langevin equation using a perturbation approach in which the small parameter represents the inverse of the number of oscillators in the bath, elucidating the relationship between finite-size and infinite-size bath responses.

Vibration absorption using non-dissipative complex attachments with impacts and parametric stiffness

Studies on prototypical systems that consist of a set of complex attachments, coupled to a primary structure characterized by a single degree of freedom system, have shown that vibratory energy can be transported away from the primary through use of complex undamped resonators. Properties and use of these subsystems as by energy absorbers have also been proposed, particularly using attachments that consist of a large set of resonators. These ideas have been originally developed for linear systems and they provided insight into energy sharing phenomenon in large structures like ships, airplanes, and cars, where interior substructures interact with a master structure, e.g., the hull, the fuselage, or the car body. This paper examines the effects of nonlinearities that develop in the attachments, making them even more complex. Specifically, two different nonlinearities are considered: (1) Those generated by impacts that develop among the attached resonators, and (2) parametric effects produced by time-varying stiffness of the resonators. Both the impacts and the parametric effects improve the results obtained using linear oscillators in terms of inhibiting transported energy from returning to the primary structure. The results are indeed comparable with those obtained using linear oscillators but with special frequency distributions, as in the findings of some recent papers by the same authors. Numerically obtained results show how energy is confined among the attached oscillators.

Wearable and mobile system to manage remotely heart failure

Cardiovascular diseases (CVDs) account for 45% of all deaths in the western world according to the 2004 World Health Organization statistics report. Heart failure (HF), CVD's primary paradigm, mainly affects people older than 65. The European MyHeart Project's mission is to empower citizens to fight CVD by leading a preventative lifestyle and allowing early diagnosis. This paper presents the iterative design and development of the HF management system, part of MyHeart Project. The system daily measures vital body signals to assess HF. The methodology applied herein has involved stakeholders in an iterative process: concept validation, feasibility, efficiency, patients' experience, and patients' acceptance. The final solution allows patient self-management of their chronic condition.

Energy equipartition and frequency distribution in complex attachments

As reported in several recent publications, an undamped simple oscillator with a complex attachment that consists of a set of undamped parallel resonators can exhibit unusual energy sharing properties. The conservative set of oscillators of the attachment can absorb nearly all the impulsive energy applied to the primary oscillator to which it is connected. The key factor in the ability of the attachment to absorb energy with near irreversibility correlates with the natural frequency distribution of the resonators within it. The reported results also show that a family of optimal frequency distributions can be determined on the basis of a variational approach, minimizing a certain functional related to the system response. The present paper establishes a link between these optimal frequency distributions and the energy equipartition principle: optimal frequency distributions are those that spread the injected energy as uniformly as possible over the degrees of freedom or over the modes of the system. Theoretical as well as numerical results presented support this point of view.

Pseudo-damping in undamped plates and shells

Pseudo-damping is a counter-intuitive phenomenon observed in a special class of linear structures that exhibit an impulse response characterized by a decaying amplitude, even in the absence of any dissipation mechanism. The conserved energy remains within but designated parts of the system. Pseudo-damping develops when the natural frequency distribution of the system includes condensation points. The recently formulated theoretical foundation of this phenomenon, based on mathematical properties of special trigonometric series, makes it possible to describe a class of mechanical systems capable of displaying pseudo-damping characteristics. They include systems with discrete oscillators and one-dimensional continuous beamlike structures already reported by the authors in recent studies. This paper examines development of pseudo-damping phenomenon in two-dimensional structures, using plates and shells as examples, and shows how a preloaded plate on an elastic foundation can lead to pseudo-damping. Moreover, in the case of curved shell elements examined here, pseudo-damping can result due to the curvature of the structure, which naturally introduces condensation points in the modal density.

Theoretical foundations of apparent-damping phenomena and nearly irreversible energy exchange in linear conservative systems

This paper discusses a class of unexpected irreversible phenomena that can develop in linear conservative systems and provides a theoretical foundation that explains the underlying principles. Recent studies have shown that energy can be introduced to a linear system with near irreversibility, or energy within a system can migrate to a subsystem nearly irreversibly, even in the absence of dissipation, provided that the system has a particular natural frequency distribution. The present work introduces a general theory that provides a mathematical foundation and a physical explanation for the near irreversibility phenomena observed and reported in previous publications. Inspired by the properties of probability distribution functions, the general formulation developed here is based on particular properties of harmonic series, which form the common basis of linear dynamic system models. The results demonstrate the existence of a special class of linear nondissipative dynamic systems that exhibit nearly irreversible energy exchange and possess a decaying impulse response. In addition to uncovering a new class of dynamic system properties, the results have far-reaching implications in engineering applications where classical vibration damping or absorption techniques may not be effective. Furthermore, the results also support the notion of nearly irreversible energy transfer in conservative linear systems, which until now has been a concept associated exclusively with nonlinear systems.

Near-irreversibility in a conservative linear structure with singularity points in its modal density

Through two complementary approaches, using modal response and wave propagation, the analyses presented here show the conditions under which a decaying impulse response, or a nearly irreversible energy trapping, takes place in a linear conservative continuous system. The results show that the basic foundation of near-irreversibility or apparent damping rests upon the presence of singularity points in the modal density of dynamic systems or, analogously, in the wave-stopping properties associated with these singularities. To illustrate the concept of apparent damping in detail, a simple undamped beam is modified to introduce a singularity point in its modal density distribution. Simulations show that a suitable application of a compressive axial force to an undamped beam placed on an elastic foundation attenuates its impulse response with time and develops the characteristics of a nearly irreversible energy trap.

Assessment of child neurology outpatients with headache, dizziness, and fainting

Neurologic symptoms such as headache, vertigo, dizziness, and fainting can create a diagnostic problem in pediatric neurology practice because they are also the most common presenting symptoms of psychiatric disorders. Children, especially adolescents, who are often admitted with such autonomic symptoms, are frequently misdiagnosed. In this study, we aimed to investigate the psychiatric morbidity and comorbidity rate in children and adolescents presenting with neurologic symptoms such as headache, vertigo, and syncope. We investigated 31 children who presented with these symptoms. All children were evaluated for their medical history and had a physical and neurologic examination. We attempted to rule out a possible organic etiology. All patients received a complete laboratory examination (blood count, electroencephalography), pediatric cardiology and otorhinolaryngology consultations, and a caloric test. All patients were assessed according to Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) criteria. The majority of the patients (93.5%) received a psychiatric diagnosis according to the DSM-IV criteria. Most of these patients were adolescents and female. Psychosocial stressors such as academic problems, familial dysfunction, parental psychopathology, and child sexual abuse were associated with somatic symptoms. The results of this study demonstrated the importance of differential diagnosis and psychiatric comorbidity in a pediatric neurologic outpatient population. Treatment should be directed at biopsychosocial integrity, and a multidisciplinary treatment approach should be applied.

Calcinosis cutis universalis

We report the case of a 49-year-old female who complained of hardening of the skin, with onset about 1.5 years before presentation. The laboratory data showed normal biochemistry profile. Routine haematochemical examinations showed slight anaemia, an increased erythrocyte sedimentation rate and negative rheumatological markers. Calcium excretion in a 24-h urine sample was normal, but the phosphate excretion was slightly low. The clinical diagnosis was verified by soft tissue ultrasound examination showing subcutaneous calcifications. X-ray examination of bones evidenced no abnormal calcification. Mammography revealed deep seated bilateral reticular calcifications, even in the axillary region. Histological examination showed calcinosis cutis. On these grounds, the diagnosis of idiopathic universal calcinosis cutis was made. The authors describe the clinical and histological picture and discuss the laboratory findings.

Assessment of depression in subjects with psoriasis vulgaris and lichen planus

AIM

The aim of this study was to investigate the frequency of depressive symptoms in psoriasis vulgaris and lichen planus and to evaluate the relationship between the Beck depression scores and the Psoriasis Area and Severity Index (PASI) scores of subjects with psoriasis vulgaris.

SUBJECTS

The study involved 120 subjects attending the dermatology clinic of Izmir Ataturk Training Hospital (Izmir, Turkey) and comprised 50 subjects with psoriasis vulgaris, 30 with lichen planus and 40 healthy control subjects.

RESULTS

Subjects with psoriasis vulgaris, lichen planus and controls had depression scores of 58%, 53% and 20%, respectively. The Beck depression scores of patients with psoriasis vulgaris were significantly higher than those of the control group. The PASI scores showed a correlation with Beck depression scores. Smoking and drinking were very common in subjects with psoriasis vulgaris. There was no correlation between the duration of illness and depressive symptoms.

CONCLUSIONS

This study confirms the importance of depressive symptoms in two common dermatological diseases. It is important to recognize this association as it affects both clinical outlook and response to treatment.

Dissipation in solids: thermal oscillations of atoms

Dissipation in solids describes conversion of kinetic energy to thermal energy. Heat capacity of a solid relates to the kinetic energy of the oscillations of its atoms with the assumption that they are in thermal equilibrium. Previous studies investigated criteria related to thermal relaxation, the process by which thermal equilibrium is established. They examined conditions for irreversible distribution of energy among the modes of a nonlinear periodic structure that represents atoms in a solid. These studies all point to the chaotic behavior of a freely vibrating nonlinear lattice as the kernel of the problem in addressing thermal relaxation. This paper extends the results of previous studies on thermalization to modeling of dissipation as energy absorption that takes place during forced vibration of particles in a nonlinear lattice. Results show that dissipation and chaotic behavior of the particles develop simultaneously. Such behavior develops when the forcing frequency falls within a resonance band. The results also support the argument that for a real solid, both in terms of size and complexity, resonance bands overlap significantly broadening the frequency range within which dissipation takes place.

Comparison of Laparoscopic and Open Ligation of the Testicular Vein in Bilateral Varicocele

In this study, we aimed to compare the advantages and disadvantages of open varicocelectomy with Kelami's incision versus laparoscopic varicocelectomy in bilateral varicoceles. We performed bilateral varicocelectomy by infrapubic incision in 43 patients with bilateral varicocele in our clinic between November 1995 and June 1997. The results of this method were compared with laparoscopic varicocelectomy results taken from literature. Open surgery has been found more advantageous in relation to the type of anesthesia, duration of the operation, complications and cost-effectiveness. There is no significant difference between the two methods with regard to the time of returning to normal activity. But, postoperative analgesic requirement in open surgery is more than in laparoscopic varicocelectomy. It is not fully known which method is best in varicocele treatment. In our clinic, however, open surgical ligation with Kelami's incision is preferred in bilateral varicocelectomies until a certain concensus is held about this treatment.

A Theoretical and Experimental Investigation of Contact Loss in the Clearances of a Four-Bar Mechanism

The dynamic behavior of a four-bar mechanism with a clearance at any one of its connections is described using a quasi-static model. Prediction of separation at the joints is based on the deviation of the model at these positions from the zero-clearance values. Corresponding experimental studies have verified the theoretical results satisfactorily. Furthermore, the present model was applied successfully to similar cases published earlier. The existing criteria on the prediction of contact loss are discussed and a new criterion is offered.

Comparison between the effects of continuous and impact noise on cochlear potentials in guinea pigs

Cochlear microphonics (CM), action potentials (AP), and endocochlear potential (EP) were recorded from anesthetized, immobilized guinea pigs during potential (EP) were recorded from anesthetized, immobilized guinea pigs during and following 20 min periods of noise exposure. Changes in cochlear potentials were compared in guinea pigs exposed to continuous broadband noise or mechanically generated impact noise of equal energy content. Over a range of continuous noise levels from 95 to 105 dB SPL it was found that continuous noise produced less suppression of CM and a greater suppression of AP than did impact noise of equal energy. A reduction of EP did not accompany CM suppression with either type of noise exposure. Suppression of CM and AP was also compared in guinea pigs with chronically implanted round window electrodes. In these preparations, AP was suppressed to a similar extent by impact and continuous noise of equal energy, but CM was suppressed to a significantly greater extent by impact noise. The data from both series of experiments indicate that the suppression of cochlear responses is not predicted by an "equal energy" rule when impact and continuous noise are compared.